The city’s opposition-held eastern neighborhoods have groaned under a regime-imposed siege for more than 90 days, according to a joint statement issued by Aleppo’s pro-opposition health directorate and city council, along with activists and local civil defense officials.

Citing statistics provided by the city council, the statement asserted that eastern Aleppo had been subject to more than 2,300 attacks within the last 23 days.

The attacks -- carried out by both Russian warplanes and Syrian regime aircraft -- have included "airstrikes, barrel-bomb attacks, artillery, cluster bombs, bunker-busting munitions, and explosive devices containing chlorine gas", according to the statement.

Within the last week alone, attacks have targeted eight medical facilities (including hospitals), six schools, two bakeries and a civil-defense office, the statement alleged.

"Both Russian and Syrian regime aircraft are intentionally targeting Aleppo’s civilian infrastructure with a view to breaking the people’s will," the statement read.

"For almost six years -- during which more than 500,000 people have died -- we have wondered what the world was doing," it added.

"How many hospitals and schools must be destroyed before action is taken to stop these war crimes?" the statement’s signatories asked.

They went on to say that some 271,000 people trapped in eastern Aleppo faced the twin threats of violence and starvation.

"The dysfunctional state of the world is responsible for some 500,000 deaths and the fate of the more than 271,000 people trapped in the city," read the statement.

Statement signatories went on to demand that that the international community "use its diplomatic leverage" to force Russia and the Assad regime to halt the bombardments and allow humanitarian aid into the city.

"The international community will be held responsible for the consequences of the ongoing siege," they said.

Anadolu Agency